TY - JOUR
TI - EXERCISE-INDUCED QRS PROLONGATION IN PATIENTS WITH CORONARY-ARTERY
DISEASE - A MARKER OF MYOCARDIAL-ISCHEMIA
AU - MICHAELIDES, A
AU - RYAN, JM
AU - VANFOSSEN, D
AU - POZDERAC, R and
AU - BOUDOULAS, H
JO - American Heart Journal
PY - 1993
VL - 126
TODO - 6
SP - 1320-1325
PB - Mosby Year Book Inc
SN - 0002-8703, 1097-6744
TODO - 10.1016/0002-8703(93)90529-I
TODO - null
TODO - The objective of this study was to investigate the effect of myocardial
ischemia on the QRS duration in patients with coronary artery disease
since acute myocardial ischemia decreases conduction velocity through
the ischemic myocardium and may produce QRS prolongation on the surface
electrocardiogram. One hundred fifty patients who underwent cardiac
catheterization and exercise radionuclide ventriculography within 1
month of each other were studied. Forty patients had normal coronary
arteries and 110 had coronary artery disease. QRS duration decreased
with exercise in patients with normal coronary arteries (-3.0 msec,
confidence limits -6.2 to 0.2), but increased in patients with coronary
artery disease; exercise-induced QRS prolongation was directly related
to the number of diseased vessels (4.8 msec in patients with one, 7.8
msec in patients with two, and 13.3 msec in patients with three-vessel
disease, p < 0.001). Likewise, QRS duration decreased with exercise in
patients without exercise-induced segmental contraction abnormalities
(-1.8 msec, confidence limits -3.7 to 0.1), but increased in patients
with segmental contraction abnormalities (6.7 msec in patients with one,
13.5 msec in patients with two, and 21 msec in patients with three
segmental contraction abnormalities, p < 0.0001). Exercise-induced QRS
prolongation was better related to the number of segmental contraction
abnormalities than to the number of diseased vessels (p < 0.01). It was
concluded that exercise produces QRS prolongation in patients with
coronary artery disease in direct relation to the number of diseased
vessels and to exercise-induced segmental contraction abnormalities.
This QRS prolongation was more closely related to the number of
exercise-induced segmental contraction abnormalities than to the number
of diseased vessels. Thus exercise-induced QRS prolongation in patients
with coronary artery disease may be a marker of exercise-induced
myocardial ischemia.
ER -